That broken egg will probably fill up with bad bacteria as days go on. Just toss it. For the first 18 days, I keep my humidity about 28-30%, the last 3 days around 70%. The first 18 days,the egg needs to lose alot of water, so it needs low humidity that pulls the moisture out.
I think it's great that you are hatching with a home made incubator! I wish I would have done that with my daughter when she was small. But now she's 32 and it's too late!